Much effort has been expended in recent years to find an effective and superior way of administering drugs to patients"" bodies. Products such as the transdermal patch and once-a-day orally administered pills that more precisely deliver drugs have been developed. Such products are a boon to patients for they boost the effectiveness of the drugs and limit side effects by precisely controlling how quickly drugs are released in the body; by keeping drugs at a constant level and by delivering them exactly where needed.
One such development is the injection or implantation of drugs in the form of in microscopic particles or pellets at a disease site. The drugs are encapsulated in polymers or fatty compounds, such as liposomes which permit slow release of the encapsulated drug over time thereby potentially lowering the drugs toxicity.
In addition, there are times when it is desirable to deliver a biological agent that is in a non-conventional form to a disease site such as a drug in a loose particulate form, or a quantity of cells, cell clusters or cellular extracts in a bibcompatible solution. A particulate biological agent can be in a granular, powdered, or microsphere form. The problem with biological agents in these forms is that they are difficult to properly deliver to a diseased tissue site.
The present invention provides a novel device with a distal end insertable into the tissue or a body cavity of a patient for delivering both particulate and liquid biological agents in a quick, predictable, safe and easy manner without damaging the biological agent. This is important in the delivery of cells or microspheres.
The present invention is directed to a biological agent delivery device including a sheath having a longitudinally extending wall surrounding an interior region, and a closed tip at a distal end. A flexible pouch formed in the sheath wall for containing a biological agent is capable of being displaced radially or laterally outwardly for radially displacing the biological agent.
In preferred embodiments, a displacement member is disposed within the sheath for causing displacement of the pouch radially with respect to the sheath to radially or laterally deliver the biological agent. The sheath is flexible and the pouch is preformed in the sheath wall. A guide wire extends within the sheath for guiding the delivery device. Preferably, the pouch system encircles the sheath. In one preferred embodiment, the displacement member includes a spring member. In another preferred embodiment, the displacement member includes a volume of fluid. The volume of fluid can be either a liquid or a gas. Optionally, a light source is included for directing light within the sheath. The light is transmitted to the tip of the delivery device by the fluid within the sheath. In yet another embodiment, the light is transmitted to the tip of the delivery device by a fiber optic disposed within the sheath. The tip is formed in a manner to produce or deliver a desired pattern of light. In still another preferred embodiment, a balloon extends from the sheath for controlling fluid flow within body cavities.